Florida has more fern species than any other state in the mainland United States, and CREW is working with partners at Fairchild Tropical Botanic Garden in Miami, Florida, to help propagate several of the most endangered from rapid urbanization and habitat loss.
The gridscale maiden fern, Thelypteris patens, is a large, beautiful fern that can reach over five feet in height. The patens variety is known only from the pine rockland habitat in Miami-Dade County and is listed as endangered in Florida. The population in one particular preserve declined to a single plant, which died in 2013.
However, before it died, researchers from Fairchild Tropical Botanic Garden collected spores from that plant and sent them to CREW’s Plant Lab here at the Cincinnati Zoo & Botanical Garden. CREW plant scientists germinated the spores in test tubes (in vitro) to produce tiny gametophytes, which represent the first stage in the fern life cycle.
These were then nurtured further in culture to produce sporophytes, which represent the second stage of fern growth and are the plants we normally think of as ferns. The sporophytes were acclimatized to soil at CREW, and then over 200 of these plants were sent to collaborators at Fairchild Tropical Botanic Garden where they were grown further in their greenhouses.
Finally, in May and June of last year, over 150 of the ferns propagated at CREW were outplanted back into the preserve where the species had been extirpated.
The plants are being monitored by Fairchild Tropical Botanic Garden. As of February 2015, the plants have had an 89% survival rate.